Pyrolytic Graphite Platform Research Articles

Direct determination of traces of copper, zinc, lead, cobalt, iron and cadmium in bovine liver by graphite furnace atomic absorption spectrometry using the solid sampling and the platform techniques

A simple and rapid method is described for direct determination of traces of Cu, Zn, Pb, Co, Fe and Cd in NBS bovine liver, SRM 1577, by graphite furnace atomic absorption spectrometry. The solid sampling technique was used, thereby avoiding the dilution factor involved in the solution technique, and also the risk of contamination from the environment in sample handling and from reagents, solvents and vessels. The organic matrix was burnt off and removed by using a well-defined selective volatilization technique combined with the analyte modification technique. Also, the effect of the platform technique in removing matrix interferences was studied using an anisotropic pyrolytic graphite platform inside the commercial graphite tube. The results of the “with platform” and the “without platform” techniques were equally accurate, but the “with platform” technique gave better precision.

Atomic absorption spectrometric determination of Cd, Pb, Zn, Cu, Co and Fe in oyster tissue by direct atomization from the solid state using the graphite furnace platform technique

This paper describes a simple and rapid method for direct determination of traces of Cu, Zn, Pb, Co, Fe and Cd in the NBS oyster tissue, SRM No. 1566, by graphite furnace atomic absorption spectrometry. The solid sampling technique has been used and this results in much higher relative sensitivity by avoiding large dilution factors involved in the sample dissolution technique. The solid sampling technique also greatly reduces or eliminates serious risk of introducing contamination and/or loss of analytes involved in sample dissolution. The organic matrix of the oyster tissue is burnt off and removed by using a well-defined selective volatilization technique. Loss of Cd during charring (pyrolysis) stage is prevented by forming a relatively thermally stable compound of cadmium by adding (NH 4 2SO 4 solution to the oyster tissue sample. Also, quantitative data are presented on the effectiveness of the platform technique in removing matrix interferences. The platform technique uses an anisotropic pyrolytic graphite platform which is inserted into a commercial graphite tube.